This invention relates to a machine for applying a plastic film on the ground, and more specifically, an agricultural implement provided with means for securing and anchoring the film to the ground when the machine turns about at the ends of a field.
Mulching apparatus for applying a photodegradable plastic film, or mulch, on seed beds are getting more and more widespread. Such machines are described in the following French Patents which are given as an illustration: Nos. 1 356 657, 2 427 780, 2 476 970, 2 452 871, 2 453 600 and 2 483 380.
These machines are suitably secured to a 3-point hitching arrangement behind a farm vehicle such as a tractor. They include main framing members which are fitted with a roll of film passing around a pair of laterally spaced press wheels which seat the edges of the film into two parallel side furrows opened in the soil by plowing means fitted on the machine in front of the lateral spaced press wheels. Behind these, closing furrow ploughshares cover up the side edges of the film with soil or dirt so as to anchor it. Behind the press wheels are usually placed seed-wheels which are also fitted with piercing means to penetrate the film and place seed in the soil. Also, some machines are adapted with knifes which will enable cutting of the film automatically at the end of the row.
At the end of the row, the whole apparatus is raised up from the ground by the 3-point hitch of the tractor. The film can then be cut or severed from the film roll at a point behind the press wheels but the part of the film which has already been unwound from the film roll or reel is creased or ruined while the tractor turns about and moves to the beginning of the next seed bed row before starting off again. The film then has to be replaced under the spaced press wheels which is not an easy matter. The film can also be cut in front of the lateral press wheels but, in this case, before the vehicle commences moving, a piece of film long enough to enable it to be positioned correctly under the press wheels will have to be unwound by hand. All these operations are strenuous because the seed wheels do not allow easy access to the film roll thereby requiring a loss of time and one or two people for the job. Since usually two or four devices are placed in parallel behind a tractor, it is still more difficult to get near the film to perform the needed tasks indicated above.
A first object of the present invention is to provide a means of eliminating nearly all the manual film operations required at the end of a row and to enable the tractor's operator to perform all these steps without moving from his seat.
According to one of the objects of the invention, it is planned to provide a mulching machine on which, behind the press wheels, is adapted, at the extremity of arms which are pivotably mounted around a crosswise horizontal axis, a crosswise shovel-like cutter blade. These arms are fixedly attached to parallel piston jacks which are integrated into the main frame part of the apparatus. The rotating axis height of the jacks can be adjusted depending on the ground, so as to make the jacks orient the cutter above the ground when the vehicle is moving or in a seeding position. When the vehicle is no longer moving, as when it has reached the end of the seed bed row, the jacks will make the cutters perform through an arc of a circle downwardly into the ground and rearwardly during which the cutter blade cuts the film from the roll or reel to leave a ground end and a reel end, folds the ground end of the film backwards on itself and gathers and deposits some soil on the folded ground end. When the device is in a start up position at the beginning of the next row, the jacks will make the cutter perform in reverse; that is, through an arc of a circle downwardly into the ground and forwardly to deposit some soil on the reel end of the film to be laid on the new seed bed.
According to another object of the present invention, the cutter has a Y-profile formed by the blade and mould boards so that the blade can both cut and carry soil.
According to another object of the present invention, it is planned to connect to the frame behind each press wheel a wheel blocking element attached at the end of a rod like member which pivots around a horizontal axle and is driven by a jack. The width of the blocking element is about the same as that of the press wheel, the rod's axis is located slightly behind axis of the press wheels, and the length of the rod is about the same as the press wheel's radius. The blocking element is formed perpendicular to the rod and can be rotated clockwise to engage and lock the respective press wheel to prevent it from turning.
According to another characteristic of the invention, the plowing means which forms each laterally spaced furrow consists of a plowing disc whose axis is oriented so that its meeting point with the axis of the other plow disc will be situated to the front of the plow discs. Such orientation causes soil to be moved inwardly of the machine to form a soil bed. A transversal press roll for compacting the soil bed has its axle supporting, at each extremity, a concave disc facing to the outside. The center cap of each concave disc penetrates inside the press roll cylinder with the roll and concave disc turning loose around said axle to form and shape the soil into a soil bed. Behind each concave disc a press wheel is located with its lower edge at a level with the bottom of the furrow.
According to another characteristic of the invention, a film dispenser means is added which consists of press wheels, a transversal cylinder turning loosely, a film spool or reel resting on the press wheels and the film which is unwound from the reel is laid down in a path around the loosely turning transversal cylinder and beneath the press wheels.